Sensor array and method of controlling sensing devices generating detection results at different frequencies and related electronic device

ABSTRACT

An electronic device includes: a sensing system having a first sensing device, for selectively detecting an object to generate a first detection result at a first frequency, wherein the first detection result indicates a state of motion of the object; a second sensing device for selectively detecting the object to generate a second detection result at a second frequency that is different from the first frequency, wherein the second detection result indicates whether the object is in a specific space; a light emitting device, for illuminating the object to make the first sensing device able to detect the state of motion of the object; and a control unit, coupled to the first sensing device and the second sensing device, for controlling operating states of the first sensing device and the second sensing device according to the first and the second detection results.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 14/055,894, filed on Oct. 17, 2013, the contents ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to video detection, and more particularly,to a method that is able to reduce power consumption of a gesturesensor, and a related electronic device and sensor array.

2. Description of the Prior Art

A sensing device of recognizing gesture (i.e., gesture sensor) is widelyused in a variety of applications, providing an innovative andinstinctive way of interacting human with machine, which detects motionof a hand of a user and accordingly issues control commands to a userinterface. Generally, the sensing device of recognizing the gestureincludes components as shown in FIG. 1. An active light source 110periodically illuminates the hand and a sensing device 120 periodicallydetects changes of lights and shadows generated by illumination on thehand. Computation circuit inside the sensing device 120 determineswhether the motion of the hand matches specific gesture patterns andaccordingly generates control commands. Operating frequencies of theactive light source 110 and the sensing device 120 are illustrated inFIG. 2A. When the hand leaves from a sensing covering range V of thesensing system 100, the active light source 110 and the sensing device120 stop periodically operating. Then, a standby mode is entered suchthat power consumption can be saved. In the meantime, the active lightsource temporarily stops illuminating the hand of the user. Also, thesensing device 120 temporarily stops sampling changes of lights andshadows. In order to re-activate the sensing system 100 when the handsenter the sensing covering range again, the active light source 110 andthe sensing device 120 intermittently detect whether the hand enter thesensing covering range V again (at a operating frequency which is lowerthan a operating frequency of the normal operating state). Once there isno change found between the lights and the shadows, the sensing system100 remains in the standby mode. Otherwise, the sensing system 100 comesback to the normal operating state, performing gesture recognition.Operating frequencies regarding the active light source 110 and thesensing device 120 is illustrated in FIG. 2B.

However, as the active light source 110 and the sensing device 120intermittently detects changes of the lights and the shadows,re-activation of the sensing system 100 may be delayed if the sensingdevice 120 cannot capture the motion of the hand immediately (i.e., thehand moves too fast). This is because the sensing system 100 is operatedat a relatively low frequency under the standby mode and may miss themotion of the hand. As a result, the user feels delay when trying tore-activate the sensing system from the standby mode.

SUMMARY OF THE INVENTION

With this in mind, it is one objective of the present invention toprovide detection and re-activation mechanism of a gesture senor under astandby mode, which utilizes an auxiliary sensing device to continuallydetects the hand instead of intermittently activating the gesture sensorto detect the hand. Therefore, the motion of the hand will not be missedand the gesture sensor can enter the normal operating state once theuser tries to do so. Embodiments of the present invention provide avariety of ways for implementing the auxiliary sensing device, all ofwhich cost less power than intermittently activating the gesture sensor.

According to one embodiment, an electronic device is provided. Theelectronic device comprises a sensing system having a first sensingdevice, a second sensing device, a light emitting device and a controlunit. The sensing system having the first sensing device is utilized forselectively detecting an object to generate a first detection result ata first frequency, wherein the first detection result indicates a stateof motion of the object. The second sensing device is utilized forselectively detecting the object to generate a second detection resultat a second frequency that is different from the first frequency,wherein the second detection result indicates whether the object is in aspecific space, The light emitting device is utilized for illuminatingthe object to make the first sensing device able to detect the state ofmotion of the object. The control unit is coupled to the first sensingdevice and the second sensing device and utilized for controllingoperating states of the first sensing device and the second sensingdevice according to the first and the second detection results.

According to one embodiment, a sensor array is provided. The sensorarray comprises: a plurality of first sensing units and at least onesecond sensing unit. The plurality of first sensing units is utilizedfor selectively detecting an object to generate a first detection resultat a first frequency, wherein the first detection result indicates astate of motion of the object. The at least one second sensing unit isutilized for selectively detecting the object to generate a seconddetection result at a second frequency that is different from the firstfrequency, wherein the second detection result indicates whether theobject is in a specific space; wherein operating states of the pluralityof first sensing units and the at least one second sensing unit aredetermined according to the first and the second detection results; andthe plurality of first sensing units and the at least one second sensingunit are disposed on a same plane and in a same chip.

According to one embodiment, a method of controlling sensing devices isprovided. The method of controlling sensing devices comprises: utilizinga first sensing device to selectively detect an object to generate afirst detection result at a first frequency, wherein the first detectionresult indicates a state of motion of the object; utilizing a secondsensing device to selectively detect the object to generate a seconddetection result at a second frequency that is different from the firstfrequency, wherein the second detection result indicates whether theobject is in a specific space; and controlling operating states of thefirst sensing device and the second sensing device according to thefirst and the second detection results; wherein the first sensing deviceand the second sensing device are disposed on a same plane and in a samechip.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a representation of a conventional sensing system.

FIGS. 2A and 2B illustrate a diagram of operating frequencies ofcomponents of the conventional sensing system in a normal operatingstate and a standby mode.

FIG. 3 illustrates a representation of an electronic device according toone embodiment of the present invention.

FIG. 4 illustrates a representation of a sensor array according to oneembodiment of the present invention.

FIG. 5 illustrates a diagram of operating frequencies of components ofthe electronic device in a normal operating state and a low powerconsumption operating state.

FIG. 6 illustrates a diagram of relationship between the timing of acontrol command and power consumption level of operating frequencies ofcomponents of the electronic device in a normal operating state and alow power consumption operating state components of the electronicdevice.

FIG. 7 illustrates a flow chart of a method of controlling sensingdevices according to one embodiment of the present invention.

DETAILED DESCRIPTION

Certain terms are used throughout the following descriptions and claimsto refer to particular system components. As one skilled in the art willappreciate, manufacturers may refer to a component by different names.This document does not intend to distinguish between components thatdiffer in name but not differ in functionality. In the followingdiscussion and in the claims, the terms “include”, “including”,“comprise”, and “comprising” are used in an open-ended fashion, and thusshould be interpreted to mean “including, but not limited to . . . ” Theterms “couple” and “coupled” are intended to mean either an indirect ora direct electrical connection. Thus, if a first device couples to asecond device, that connection may be through a direct electricalconnection, or through an indirect electrical connection via otherdevices and connections.

Please refer to FIG. 3, which is a representation of an electronicdevice according to one embodiment of the present invention. As shown,an electronic device 300 comprises a sensing system 310, a sensingdevice 320 and a control unit 330. The sensing system 310 could be agesture sensor, which further includes a sensing device 315. The sensingdevice 315 is arranged for selectively detecting an object (e.g. a hand)to generate a detection result SR_1. The detection result SR_1 indicatesa state of motion of the object. The sensing device 315 comprises asensor array as well as related computation and/or control circuits. Thesensing device 320 is arranged for selectively detecting the object togenerate a detection result SR_2. The detection result SR_2 is able toindicate whether the object is in a specific space L (i.e., a sensingcovering range of the sensing system 310). The control unit 330 iscoupled to the sensing device 315 and the sensing device 320, and isarranged for controlling operating states of the sensing device 315 andthe sensing device 320 according to the detection results SR_1 and SR_2.

By the detection result SR_1 and the detection result SR_2, theactivation or operating states of the sensing device 315 and the sensingdevice 320 can be determined. When the detection result SR_1 indicatesthat the object leaves from the specific space L or the object ismotionless, the control unit 330 issues the control command S_command1to the sensing device 315, allowing the sensing device 315 to enter alow power consumption operating state or stop operating. At this time,the sensing device 315 temporarily stops generating the detection resultSR_1 to save power consumption. More specifically, the present inventionanalyzes several detection results SR_1 sampled during a period of time.Once it is found that there is no obvious difference between thesedetection results SR_1 (i.e. the object is motionless) or the objectleaves from the specific space L (i.e. the detection result SR_1indicates a sudden change occurs and then remains unchanged), thecontrol unit 330 will send the control command S_command1 to the sensingsystem 310. By turning off/lowering down power that is supplied to areadout circuit, a selecting circuit, a reset circuit or other circuitcomponents of the sensing device 315, and/or turning off a lightemitting device 312 of the sensing system 310, the power consumption canbe reduce. The light emitting device 312 is used to illuminate theobject such that the sensing device 315 is able to detect the state ofmotion of the object according to changes of lights and shadows. At thesame time, the control command S_command1 issued by the control unit 330will be also sent to the sensing device 320, allowing the sensing device320 to enter a normal operating state, generating the detection resultSR_2. Afterward, the control unit 330 determines whether to re-activatethe sensing device 315 and turn on the light emitting device 312according to the detection result SR_2. Therefore, it can be determinedwhether to allow the sensing system 310 to enter the normal operatingstate.

Compared to the conventional art, the sensing device 315 of the presentinvention does not intermittently activate to detect the state of motionof the object when it enters the low power consumption operating state.Instead, the auxiliary sensing device 320 of simple circuitry and lowconsumption is used to detect the state of motion of the object. In oneembodiment, the sensing device 320 could be an ambient light sensor or aproximity sensor. Such device cost much less power than the sensingdevice 315 comprised of a lot of sensing units. Although the sensingdevice 320 cannot recognize the gesture of the hand but it can detectwhether the object (e.g. the hand) is in the specific space L. Since thespecific space L represents the sensing covering range of the sensingsystem 310, it is unnecessary to re-activate the sensing device 315 andallow the sensing device 315 to enter the normal operating state if theobject is not in the specific space L. Only when the object is in thespecific space L, the sensing device 315 needs to be activated.

In addition to the ambient light sensor or the proximity sensor, itstill has other different ways to realize the sensing device 320. In oneembodiment, the sensing device 320 and the sensing device 315 could beportions of a sensor array, respectively. Please refer to FIG. 4. Acenter portion of sensing units of a sensor array 400 is arranged as thesensing device 315, which detects the state of motion of the objectaccording to the changes of the shadows and the lights. The otherportion of the sensing units of the sensor array 400 is arranged assensing device 320, which detects whether the object is in the specificspace L. Please note that the present invention is not limited in scopeto the arrangement illustrated in FIG. 4. For example, the sensingdevice 320 could be one or more sensing units in any position of thesensor array (e.g. edge, corner or center). As the number of the sensingunits that are arranged as the sensing device 320 is smaller than thenumber of the sensing units that are arranged as the sensing device 315,the power cost by the sensing device 320 is much less than theintermittently activating the sensing device 315 to detect the state ofmotion of the object. Moreover, no matter the sensing device 320 isrealized by the ambient light sensor and the proximity sensor or isrealized by some of sensing units of the sensor array, the sensingsystem 310 and the sensing device 320 can be implemented with in asingle chip (i.e., System on Chip, SoC), thereby saving the size of thecircuit.

When the detection result SR_2 generated by the sensing device 320indicates that the object enters the specific space L again or theobject begins to move, the control unit 330 issues the control commandS_Command2, allowing the sensing system 310 to enter a normal operatingstate, detecting the state of motion of the object to generate thedetection result SR_1. Similarly, the control command S_Command2 will bealso issued to the sensing device 320, ending the operation of thesensing device 320. Operating frequencies of the sensing system 310 andthe sensing device 320 can be understood by FIG. 5.

Please refer to FIG. 6, which illustrates the relationship between powerconsumption level and the control command. When the object leaves fromthe specific space L or is motionless, the control command S_Command1 isissued, causing the power consumption level PWR_Level1 of sensing system310 to be reduced (by allowing the sensing device 315 to enter the lowpower consumption operating state or to be de-activated, and turning offthe light emitting 312), thereby stopping detecting the object. As aconsequence, the sensing device 320 is activated, entering the normaloperating state such that the power consumption level PWR_Level2 isincreased. Once the sensing device 320 indicates the lights and shadowsin the specific space L changes (i.e., the object enters the sensingcovering range again or the object begins to move), the control commandS_Command2 is issued, allowing the sensing system 310 to enter thenormal operating state. At this tine, the power consumption levelPWR_Level1 of the sensing system 310 goes back to a normal value. Also,the sensing device 320 will be de-activated or enter the low powerconsumption operating state, causing the power consumption levelPWR_Level2 to be reduced.

Based on the principles mentioned above, a method of controlling asensing device is provided according to one embodiment of the presentinvention. The method includes steps as shown in FIG. 7. At step 700,the flow starts. At step 720, it is determined that whether an objectleaves from a specific space L or is motionless. Such determination isaccomplished by referring to a first detection result (e.g. thedetection result SR_1) generated by a first sensing device (e.g. thesensing device 315). If it is determined that the object does not leavefrom the specific space or is not motionless, the flow goes back to step702 to continue determining. If it is determined that the object leavesfrom the specific space or is motionless, the flow goes to step 704,de-activating the first sensing device or allowing the first sensingdevice to enter the low power consumption operating state. At the sametime, a light emitting device corresponding to the first sensing devicemay be turned off. Also, a second sensing device (e.g. the sensingdevice 320) is activated to generate a second detection result (e.g. thesecond detection result SR_2). Afterward, the flow goes to step 706, itis determined that the object enters the specific space L again orbegins to move. If no, the flow goes back to 706. If yes, the flow goesto step 708, de-activating the second sensing device and activatingfirst sensing device to enter the normal operating state. Also, thelight emitting device is turned on such that the first sensing device isable to detect the state of motion of the object.

Reference in the specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least animplementation. The appearances of the phrase “in one embodiment” invarious places in the specification are not necessarily all referring tothe same embodiment. Thus, although embodiments have been described inlanguage specific to structural features and/or methodological acts, itis to be understood that claimed subject matter may not be limited tothe specific features or acts described. Rather, the specific featuresand acts are disclosed as sample forms of implementing the claimedsubject matter.

In conclusion, advantages of utilizing an auxiliary sensing device (i.e.sensing device 320) instead of intermittently activating the gesturesensor includes shorter re-activation time and less power consumption.This is because the auxiliary sensing device has simple circuitry andlow power consumption. Even though the auxiliary sensing device isoperated at a high frequency, the total power consumption is stilldecent. Besides, if the auxiliary sensing device is operated at the highfrequency to detect, it will not miss the state of motion of the objecteasily such that the re-activated time can be shortened. As a result,the user will not feel the delay of the re-activation.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. An electronic device, comprising: a sensingsystem having a first sensing device, for selectively detecting anobject to generate a first detection result at a first frequency,wherein the first detection result indicates a state of motion of theobject; a second sensing device for selectively detecting the object togenerate a second detection result at a second frequency that isdifferent from the first frequency, wherein the second detection resultindicates whether the object is in a specific space; a light emittingdevice, for illuminating the object to make the first sensing deviceable to detect the state of motion of the object; and a control unit,coupled to the first sensing device and the second sensing device, forcontrolling operating states of the first sensing device and the secondsensing device according to the first and the second detection results.2. The electronic device of claim 1, wherein when the first detectionresult indicates the object leaves from the specific space or the objectis motionless, the control unit allows the first sensing device to entera low power consumption operating state, and the first sensing deviceaccordingly stops generating the first detection result.
 3. Theelectronic device of claim 1, wherein when the first detection resultindicates the object leaves from the specific space or the object ismotionless, the control unit allows the second sensing device to enter anormal operating state, and the second sensing device accordinglygenerates the second detection result.
 4. The electronic device of claim1, wherein when the second detection result indicates the object entersthe specific space or the object moves, the control unit allows thefirst sensing device to enter a normal operating state, and the firstsensing device accordingly generates the first detection result.
 5. Theelectronic device of claim 4, wherein before the control unit allows thefirst sensing device to enter the normal operating state, the firstsensing device stops generating the first detection result.
 6. Theelectronic device of claim 1, wherein the control unit turns on/off thelight emitting device according to the first and the second detectionresults.
 7. The electronic device of claim 1, wherein the first sensingdevice and the second sensing device are portions of a sensor array. 8.The electronic device of claim 1, wherein the first sensing device andthe second sensing device are disposed in a same chip.
 9. The electronicdevice of claim 1, wherein the second sensing device is an ambient lightsensor or a proximity sensor.
 10. A sensor array, comprising: aplurality of first sensing units, for selectively detecting an object togenerate a first detection result at a first frequency, wherein thefirst detection result indicates a state of motion of the object; and atleast one second sensing unit, for selectively detecting the object togenerate a second detection result at a second frequency that isdifferent from the first frequency, wherein the second detection resultindicates whether the object is in a specific space; wherein operatingstates of the plurality of first sensing units and the at least onesecond sensing unit are determined according to the first and the seconddetection results; and the plurality of first sensing units and the atleast one second sensing unit are disposed on a same plane and in a samechip.
 11. The sensor array of claim 10, wherein when the first detectionresult indicates the object leaves from the specific space or the objectis motionless, the first sensing units enter a low power consumptionoperating state and stop generating the first detection result.
 12. Thesensor array of claim 10, wherein when the first detection resultindicates the object leaves from the specific space or the object ismotionless, the at least one second sensing unit enters a normaloperating state and generates the second detection result.
 13. Thesensor array of claim 10, wherein when the second detection resultindicates the object enters the specific space or the object moves, thefirst sensing units enter a normal operating state and generates thefirst detection result.
 14. The sensor of claim 13, wherein before thefirst sensing units enter the normal operating state, the first sensingunits stop generating the first detection result.
 15. The sensor arrayof claim 10, wherein the at least one second sensing unit is at an edgeof the sensor array.
 16. A method of controlling sensing devices,comprising: utilizing a first sensing device to selectively detect anobject to generate a first detection result at a first frequency,wherein the first detection result indicates a state of motion of theobject; utilizing a second sensing device to selectively detect theobject to generate a second detection result at a second frequency thatis different from the first frequency, wherein the second detectionresult indicates whether the object is in a specific space; andcontrolling operating states of the first sensing device and the secondsensing device according to the first and the second detection results;wherein the first sensing device and the second sensing device aredisposed on a same plane and in a same chip.
 17. The method of claim 16,wherein the step of controlling the operating states of the firstsensing device and the second sensing device comprises: when the firstdetection result indicates the object leaves from the specific space orthe object is motionless, allowing the first sensing device to enter alow power consumption operating state and to stop generating the firstdetection result.
 18. The method of claim 16, wherein the step ofcontrolling the operating states of the first sensing device and thesecond sensing device comprises: when the first detection resultindicates the object leaves from the specific space or the object ismotionless, allowing the second sensing device to enter a normaloperating state and to generate the second detection result.
 19. Themethod of claim 16, wherein the step of controlling the operating statesof the first sensing device and the second sensing device comprises:when the second detection result indicates the object enters thespecific space or the object moves, allowing the first sensing device toenter a normal operating state and to generate the first detectionresult.
 20. The method of claim 19, wherein the step of controlling theoperating states of the first sensing device and the second sensingdevice comprises: stopping generating the first detection result beforethe first sensing device is allowed to enter the normal operating state.